Mathematical Induction is used for direct proofs of many theorems; its logical equivalent, the Well-Ordering Property, replaced it to yield indirect proofs by contradiction. The author claims the later property is easier to comprehend and that it affords a non-geometrical example of proof by contradiction. (JP)

The minimum number and type of whole-unit weights needed to balance any object is extended to the situation where weights may be placed on both pans of a balance scale. (DT)

A method for finding a fraction having a value between two given fractions is illustrated and proved. (DT)

Some techniques are given for relating the English system of liquid measure to base two numeration. (DT)

Grade four students who studied 3, 5, 10 or 12 value systems of numeration were compared with similar students who studied only a decimal system. A test was designed to measure understanding of the decimal system, processing decimal numerals, and place-value systems in general. Data analysis using multivariate analysis of covariance is presented.…

Operations with zero and concepts associated with the use of zero are examined in some detail. Historical practices concerning zero are discussed. (CT)